# NAME
Data::Validator - Rule based validator on type constraint system
# VERSION
This document describes Data::Validator version 1.04.
# SYNOPSIS
use 5.10.0;
use Data::Validator;
# for functions
sub get {
state $rule = Data::Validator->new(
uri => { isa => 'Str', xor => [qw(schema host path_query)] },
schema => { isa => 'Str', default => 'http' },
host => { isa => 'Str' },
path_query => { isa => 'Str', default => '/' },
method => { isa => 'Str', default => 'GET' },
);
my $args = $rule->validate(@_);
# ...
}
get( uri => 'http://example.com/' );
# for methods
sub method {
state $rule = Data::Validator->new(
foo => 'Str',
)->with('Method');
my($self, $args) = $rule->validate(@_);
# ...
}
Foo->method( foo => 'bar' );
# using sequenced parameters
sub seq {
state $rule = Data::Validator->new(
foo => 'Str',
)->with('StrictSequenced');
my $args = $rule->validate(@_);
# ...
}
seq( 'bar' ); # seq() will get { foo => 'bar' }
seq({ foo => 'bar' }); # named style are NOT available!
# using Method and StrictSequenced together
sub seq_method {
state $rule = Data::Validator->new(
foo => 'Str',
)->with( 'Method', 'StrictSequenced');
my($self, $args) = $rule->validate(@_);
# ...
}
Foo->seq_method( 'bar' ); # seq() will get { foo => 'bar' }
# DESCRIPTION
This is yet another validation library, based on `Smart::Args` but
less smart.
This is designed for general data validation. For example, it is useful for CSV, JSON, XML, and so on.
## Concepts
- Natural as Perl code
I love `Smart::Args` because it is really stylish, but it does not seem
Perl-ish.
Thus, I have designed `Data::Validator` in more Perl-ish way
with full of `Smart::Args` functionality.
- Basics on type constraint system
Moose's type constraint system is awesome, and so is Mouse's. In fact,
Mouse's type constraints are much faster than Moose's so that you need not
hesitate to check types.
Thus, I have made `Data::Validator` on Mouse's type constraint system.
- Pure Perl
Although I do not hesitate to depend on XS modules, some people think that
XS modules are hard to install.
Thus, I have written `Data::Validator` in pure Perl and selected dependent
modules which work in pure Perl.
- Performance
Validators should be as fast as possible because they matter only for illegal
inputs. Otherwise, one would want something like _no validation_ option.
This is much faster than `Params::Validate`, which has an XS backend, though.
# INTERFACE
## `Data::Validator->new( $arg_name => $rule [, ...]) :Validator`
Creates a validation rule. You should cache the rules for performance.
Attributes for _$rule_ are as follows:
- `isa => $type : Str|Object`
The type of the rule, which can be a Mouse type constraint name, a class name,
or a type constraint object of either Mouse or Moose (i.e. it's duck-typed).
- `does => $role : Str|Object`
The type of the rule, which can be a Mouse type constraint name, a role name,
or a type constraint object of either Mouse or Moose (i.e. it's duck-typed).
Note that you cannot use it with the `isa` attribute.
- `coerce => $should_coercion : Bool`
If false, the rule does not try to coerce when the validation fails.
Default to true.
- `default=> $value : Any | CodeRef`
The default value for the argument.
If it is a CODE reference, it is called in scalar context as
`$default->($validator, $rule, $args)` and its return value
is used as a default value.
Because arguments are validated in the order of definitions, `default`
callbacks can rely on the previously-filled values:
my $v = Data::Validator->new(
foo => { default => 99 },
bar => { default => sub {
my($validator, $this_rule, $args) = @_;
return $args->{foo} + 1;
} },
);
$v->validate(); # bar is 100
$v->validate(foo => 42); # bar is 43
Unlike Moose/Mouse's `default`, any references are allowed, but note that
they are statically allocated.
- `optional => $value : Bool`
If true, users can omit the argument. Default to false.
- `xor => $exclusives : ArrayRef`
Exclusive arguments, which users cannot pass together.
- `documentation => $doc : Str`
Descriptions of the argument.
This is not yet used anywhere.
## `$validator->find_rule($name :Str)`
Finds the rule named _$name_. Provided for error handling.
## `$validator->with(@extensions) :Validator`
Applies _@extensions_ to _$validator_ and returns itself.
See ["EXTENSIONS"](#EXTENSIONS) for details.
## `$validator->validate(@args) :HashRef`
Validates _@args_ and returns a restricted HASH reference.
Restricted hashes are hashes which do not allow to access non-existing keys,
so you must check a key `exists` in the hash before fetching its values.
# EXTENSIONS
There are extensions which changes behaviours of `validate()`.
## Method
Takes the first argument as an invocant (i.e. class or object instance),
and returns it as the first value:
my($invocant, $args) = $rule->validate(@_);
## StrictSequenced
Deals with arguments in sequenced style, where users should pass
arguments by the order of argument rules, instead of by-name.
Note that single HASH ref argument was dealt as named-style arguments,
but this feature is NOT available since version 1.01.
## Sequenced
Deals with arguments in sequenced style, where users should pass
arguments by the order of argument rules, instead of by-name.
Note that if the last argument is a HASH reference, it is regarded as
named-style arguments.
## AllowExtra
Regards unknown arguments as extra arguments, and returns them as
a list of name-value pairs:
my($args, %extra) = $rule->validate(@_);
## NoThrow
Does not throw errors. Instead, it provides validators with the `errors`
attribute:
my $args = $v->validate(@_); # it never throws errors
if($v->has_errors) {
my $errors = $v->clear_errors;
foreach my $e(@{$errors}) {
# $e has 'type', 'message' and 'name'
print $e->{message}, "\n";
}
}
## Croak
Does not report stack backtrace on errors, i.e. uses `croak()` instead
of `confess()` to throw errors.
## NoRestricted
Does not make the argument hash restricted.
# DEPENDENCIES
Perl 5.8.1 or later.
# BUGS
All complex software has bugs lurking in it, and this module is no
exception. If you find a bug please either email me, or add the bug
to cpan-RT.
# SEE ALSO
[Smart::Args](http://search.cpan.org/perldoc?Smart::Args)
[Params::Validate](http://search.cpan.org/perldoc?Params::Validate)
[Sub::Args](http://search.cpan.org/perldoc?Sub::Args)
[MooseX::Params::Validate](http://search.cpan.org/perldoc?MooseX::Params::Validate)
[Mouse](http://search.cpan.org/perldoc?Mouse)
[Hash::Util](http://search.cpan.org/perldoc?Hash::Util) for a restricted hash.
# AUTHOR
Fuji, Goro (gfx)
# LICENSE AND COPYRIGHT
Copyright (c) 2010, Fuji Goro (gfx). All rights reserved.
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.